How does the composition of the cell membrane regulate the movement of substances into and out of the cell?

If two parents who's blood types are both b produce a child that has blood type o, what can you say about the parent's genotybes? oa) one is ii ob) one is ibi oc) both are bi od) nothing, this is impossible

How does photosynthesis show the conservation of mass and energy?

Which kind of worm has a closed circulatory system? a planarian b fluke c pinworm d an earthworm